AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0748

DTC Code DTC Name
P0748 Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)

DESCRIPTION

Changing from 1st to 6th is performed by the TCM turning shift solenoid valves SL1, SL2, SL3, SL4 and SL on and off. If an open or short circuit occurs in any of the shift solenoid valves, the TCM controls the remaining normal shift solenoid valves to allow the vehicle to be operated Click here.

DTC No. DTC Detection Condition Trouble Area
P0748

The TCM checks for an open or short in the shift solenoid valve SL1 circuit while driving and shifting between 4th and 5th gears. (1-trip detection logic)


  • Output signal duty equals 100%.

    (NOTE: SL1 output signal duty is less than 100% under normal condition.)

  • Open or short in shift solenoid valve SL1 circuit

  • Shift solenoid valve SL1

  • TCM

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The TCM commands gear shifts by turning the shift solenoid valves on or off. When there is an open or short circuit in any shift solenoid valve circuit, the TCM detects the problem and illuminates the MIL and stores the DTC. The TCM also performs the fail-safe function and turns the other normal shift solenoid valves on or off. (In case of an open or short circuit, the TCM stops sending current to the circuit.)

While driving and shifting between 4th and 5th gears, if the TCM detects an open or short in the shift solenoid valve SL1 circuit, the TCM determines there is a malfunction Click here.

MONITOR STRATEGY

Related DTCs P0748: Shift solenoid valve SL1/Range check
Required sensors/Components Shift solenoid valve SL1
Frequency of operation Continuous
Duration 1 sec.
MIL operation Immediate
Sequence of operation None

TYPICAL ENABLING CONDITIONS

All
The monitor will run whenever the following DTCs are not present None
Engine switch on (IG)
Starter OFF
Condition (A)
Battery voltage 12 V or more
Condition (B)
Battery voltage 10 V or more and less than 12 V
CPU commanded duty Less than 75%

TYPICAL MALFUNCTION THRESHOLDS

Condition (A) and (B)
Output duty cycle 100% or more

COMPONENT OPERATING RANGE

Output duty cycle More than 3% and less than 100%

WIRING DIAGRAM

A01HMP4E33

INSPECTION PROCEDURE

Note

Perform the universal trip to clear permanent DTCs Click here.

Tech Tips

The following table shows normal operation of the shift solenoid valve SL1 when the shift lever is in D:

TCM commanded gear 1st 2nd 3rd 4th 5th 6th
Shift solenoid valve SL1 ON ON ON ON OFF OFF

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (SL1)


    1. A01HQ89E52
      Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

      Remove the TCM from the transaxle.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      14 (SL1+) - 13 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω
      14 (SL1+) - Body ground and other terminals Always 10 kΩ or higher
      13 (SL1-) - Body ground and other terminals Always 10 kΩ or higher

    NG

    INSPECT SHIFT SOLENOID VALVE SL1 Click here

    OK

    REPLACE TCM Click here

  2. INSPECT SHIFT SOLENOID VALVE SL1


    1. A01HMPNE01
      Text in Illustration
      *1 Shift Solenoid Valve SL1

      Remove shift solenoid valve SL1.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect a battery positive (+) lead with a 21 W bulb to terminal 2 and a negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE SL1 Click here

    OK

    REPLACE TRANSMISSION WIRE Click here